Manufacture of bricks



CONlNG OR PLASTlC H I om'awlng.

' To all whom it may concern cation in Great under N0. 20139/19,) of which the following wumwmuar or Cross Refeieric PATENT OFFICE.

KEW GA BDENS, SURREY, GLAND.

, ,xmtixcwmer;

Be it known that I, WAL'rnnfWnlmaM CBAVVFORD, a subject of the King'o'f Great Britain 'and Ireland, residing at Cumber land House, Kew Gardens, Surrey, England, have invented certain new and useful Improvements in and Relat'in to the Manufacture of Bricks, for which have filed appliritain on December 1, 1919,

is a specification. H

' 'This invention relates to the manufacture of bricks and the like, and its ob'ect isto provide an improved rocess for t e manufacture of these artic les from almost an kind of earth or cla which may be avai able inmarticfilar locality, the products obtained moreover, being of great strength.

. and durability.

At the present time there is a great s'hortage of bricks and the like, and building operations are being seriously interfere with thereby,as well as by the hi h cost of the ordinary burnt red bricks. T e resent invention seeks to overcome these ifiiculties, by providing means whereby bricks of excellent quality can rapidly and economically be manufactured in practically any 10- cality. According to the inventlon, any kind of clay or earth, even ordinar soil, can be used for brick making, and have found that if the directions iven herein are carefully followed, bricks of great strength and durability will be obtained at a cost much below that of the ordinary burnt brick.

Various processes have in the past been roposed for making'bricks and the like, rom either clay burnt or'unburnt, or from other siliceous mater al, by mixmg cemen therewl ,an a mg water after wh1 e mixture has been pressed" into molds and the molded articles allowed to'set;

I have found however, that in order to obtain satisfactory results from a brick of this kind, it is necessary to manufacture the same with great care, and as a result of a large number of experiments, I have found that by closely following the directions given below, bucks and the like can be produced of a strength and durabihty not hitherto attained in this class of material.

The invention has the further advanta already referred to, of enabling these 1' ts fi limgjor severa hours, and air-dr ing cm at a tem erature onl 1 sl g y a 0% W convement furnace may PatentedNov. 1, 1921,

ti m: ys,i921. sem1n.4a5 41. ppcaonpe anua v r o brick dust, sand and the like, but with any able. y I

"The process which isthe subject of the ea or soil which may be availpresent invention, consists in "taking any .ind of earthand onsoi l and/or cla in e samema 11z1n a iemperature of a u .,a then mixing it with a relatively small quantity of previously dehydrated Portland or like cemen ,mo1s enln e mixture ressin it into m'olds' f'lmmersin the molde r10 s' in reezin pom a The mventlon further comprises the use of, only just suflicient warm water for moistening the burnt gangue and cement, to cause it to ball or stick together when squeezed by the hand, as well as the step of compressing the mixture into molds under a pressure of not less than '150 lbs. to the square inch. "Theinvention is carried out as follows: Any kind of clay, or ordinary eartl or soil, maybe used as the raw material. 'Ordinary earth usually consists of a mixture of uncombined alumina andsilica together a so a certain amount of oxid of is. If desired, a mixture of these matemals maybe used, and the material used will hereafter be referred to burnas 'gangue. f The ganfipe is first burnt by bein submitted 1500 in an oxidizingatmp spherg. Any bemployed for this pur se,but I have found that the oil burner escribed in my Letters Patent of Great Britain No. 2860/15, is particularly suitable for obtaining the required temperature. ,-A convenient method of burning the eeding it On to a traveling band of suitable refractory material, and causing the latter to travel at the proper speed through the furnace. The burning operation has the effect of removing all or uic or volatile matter, and I have found t at whatever the gangue used may be, it is important that it should first be burnt.

ganguejn this type 'of furnace consists in After the I gall e has been burnt, it is mixed with ort and or like cement, which has p v y i m edratanterm erature ngt expeeding: This step 1s also that if the cement has not been dehydrated an important onejdii d f have found or as ort period, 15 minutes w1 generally 'suflice, to a temperature of 2 T vr hr I: v I ,u ;-o-

before use, the quality of the resulting brick crushing strain recgired to break them after will sufi' e r.-;.; H W as 106 tons The burnt gan e is mixed with the deb per square inch.

dratedm'd rhent, in any nimble ype :Bnioksnf the high quality referred to, can myifi'iiieifm afi'ount of cement used, manufactured rapidly, and at a very being not less than it {part in 8 parts of the much smaller cost, than that of the ordinary mixture. If bricks of any particular color burnt brick, and a further great advantage are required, a powdered metallic 0x1 or oi'the process is that -it can be carried out other suitable i cut to produce that color anywhere where ordinary soil or earth is is added to'themixture at this stage. Thus obtainable. 1 q

for example, if a red brick is required, oxid I claim of iron should be added to the mixture,"un- 1. The method of manufacturing bricks ae i no less H1" e 'gangue already contains enough of and the like, which comprises burning a gigthis substance. j age WW Then the ingredients have "been thor t en mixin the burned ma ria wi a re aoughly a'nixed and jwhile they are still tiuely small quantity of dehydrated cement, being kept in motion by the rotary mixer, then moistenmg the mixture and pressing 7" water, preferabl at a temperature of about the same into form, then immersing said 6 9. l 's spraye on to the mixture. Great pressed form'in cold water, and finally drycare s ould be taken not'to add too much ing the pressed bricks at a low temperature. water to the mixture, the correct amount be- 1 2. The method of manufacturing bricks ing just enou h to moisten it sufficiently to and the like, which comprises burning a suitable gangue in an oxidizing atmosphere at a temperature 'of approximately 1500 C., then .mixin the urned material with a relaeliyfirated cement,

cause it 'to all or stick together when squeezed in the hand. I The mass is then immediately removed from the mixer, an'd quickly pressedjnto tivly sma quan 1 y o' molds, in any convenient "form 'of .press. then moistening't-he burned mixture enough The ressure used shouldin no case beless to cause the same to ballor stick together, thanmfio the square inch, although then pressing the mixture into form, then very 'much higher pressures, e. 9.121s high as" immersingsaid form in coldw'ater until the lOOjto'ns to the square foot, have beenjusetl airhubbles are removed, and finally air drywithi'a'dr'antage. V ingthe pressed bricks at a low temperature. QTh'brieks are then removed from the Y'T3I5The method of manufacturing bricks niolds and'if not sufficiently hardened, they and the like, which consists in "burning a are permited to harden or set, and are then suitable gangue in an oxidizing atmosphere immersed in cold water for several hours, at'a temperature of approximately 1500 C., and until all air liuBB les have disappeared; thnmixin the burned material with a rela- They are'then ?ir-grie'Q for several days in 'tiyely'smal quantity of dehydrated cement, a. coldjroom, 1e emperature of'which is thenmoistening'the burned mixture enough onlyyeryslightly; i to 'causethe same'to ball or stick'together,

oint. Care should howe er e t en to'see then pressing themixture into form under at f theftemp'er'ature alwa sfslightly a'pressiireof 150 ounds tothe square'inch higher than freezing point. I" avegfound then immersingt epressed bricks'in cold that the low temperature during aeration water for'several hours, and finally airdrlycauses ,a considerable increaseinthestrengtth ing said bricks at a temperature on y of the brick, and I attribute this e ifectftoithe sli' htlFHbOV E freezing point. fact-that it retards the setting of thecement, witness whereof I aflix my signature.

and consequently produces longer crystals l y during such setting. .wanrnawiLnmn-onawr ,By proceeding in the mannerdescribedfI itnesssz" have ,obtained fbrick's of excellent} texture, f ,DEHN,

c ipa j a and appearance, and very great strength, the F 

